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/* SPDX-License-Identifier: GPL-3.0-or-later */
/* Copyright 2021 - 2022, Kim Kuparinen < kimi.h.kuparinen@gmail.com > */
/**
* @file dispatch.c
* Syscall dispatch.
*/
#include <apos/canary.h>
#include <apos/debug.h>
#include <apos/uapi.h>
/** Syscall number to syscall handler conversion. */
static const sys_t syscall_table[] = {
/* noop */
[SYS_NOOP] = sys_noop,
/* debugging */
[SYS_PUTCH] = sys_putch,
/* mem */
[SYS_REQ_MEM] = sys_req_mem,
[SYS_REQ_PMEM] = sys_req_pmem,
[SYS_REQ_FIXMEM] = sys_req_fixmem,
[SYS_FREE_MEM] = sys_free_mem,
/* timers */
[SYS_TIMEBASE] = sys_timebase,
[SYS_REQ_REL_TIMER] = sys_req_rel_timer,
[SYS_REQ_ABS_TIMER] = sys_req_abs_timer,
[SYS_FREE_TIMER] = sys_free_timer,
/* ipc */
[SYS_IPC_SERVER] = sys_ipc_server,
[SYS_IPC_REQ] = sys_ipc_req,
[SYS_IPC_FWD] = sys_ipc_fwd,
[SYS_IPC_RESP] = sys_ipc_resp,
/* proc */
[SYS_CREATE] = sys_create,
[SYS_FORK] = sys_fork,
[SYS_EXEC] = sys_exec,
[SYS_SIGNAL] = sys_signal,
[SYS_SWAP] = sys_swap,
/* conf */
[SYS_CONF_SET] = sys_conf_set,
[SYS_CONF_GET] = sys_conf_get,
[SYS_POWEROFF] = sys_poweroff,
};
/**
* Noop syscall handler.
*
* @return \ref OK and \c 0.
*/
SYSCALL_DEFINE0(noop)(){
info("sys_noop\n");
return (struct sys_ret){ OK, 0 };
}
/**
* Putch syscall handler.
*
* @param a Character to put.
* @return \ref OK and 0.
*/
SYSCALL_DEFINE1(putch)(sys_arg_t a){
const char c[2] = {a, 0};
dbg((const char *)&c);
return (struct sys_ret){ OK, 0 };
}
struct sys_ret syscall_dispatch(sys_arg_t syscall, sys_arg_t a, sys_arg_t b,
sys_arg_t c, sys_arg_t d)
{
struct tcb *t = cur_tcb();
size_t sc = syscall;
if (sc >= ARRAY_SIZE(syscall_table)) {
error("Syscall %zu outside allowed range [0 - %zu]\n", sc,
ARRAY_SIZE(syscall_table));
return (struct sys_ret){ ERR_INVAL, 0 };
}
sys_t call = syscall_table[sc];
if (!call) {
error("Syscall %zu not legitimate value\n", sc);
return (struct sys_ret){ ERR_INVAL, 0 };
}
struct sys_ret r = call(a, b, c, d);
if (check_canary(t)) {
bug("Syscall %zu overwrote stack canary\n", syscall);
return (struct sys_ret){ ERR_INT, 0 };
}
return r;
}
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